Christopher J. Durall
Chelsey Klimek, Christopher Ashbeck, Alexander J. Brook and Chris Durall
Clinical Scenario: CrossFit is a form of exercise that incorporates rapid and successive high-intensity ballistic movements. As CrossFit is an increasingly popular fitness option, it is important to determine how rates of injury compare to more traditional forms of exercise. This review was conducted to ascertain the incidence of injury with CrossFit relative to other forms of exercise. Focused Clinical Question: Are injuries more common with CrossFit training than other forms of exercise? Summary of Key Findings: (1) The literature was searched for studies that compared injury rates among individuals who participated in CrossFit fitness programs to participants in other exercise programs. (2) The search initially yielded >100 results, which were narrowed down to 3 level 2b retrospective cohort studies that were deemed to have met inclusion/exclusion criteria. (3) In all 3 reviewed studies, the reported incidences of injuries associated with CrossFit training programs were comparable or lower than rates of injury in Olympic weightlifting, distance running, track and field, rugby, or gymnastics. Clinical Bottom Line: Current evidence suggests that the injury risk from CrossFit training is comparable to Olympic weightlifting, distance running, track and field, rugby, football, ice hockey, soccer, or gymnastics. Injuries to the shoulder(s) appear to be somewhat common with CrossFit. However, the certitude of these conclusions is questionable given the lack of randomization, control, or uniform training in the reviewed studies. Clinicians should be aware that injury is more prevalent in cases where supervision is not always available to athletes. This is more often the case for male participants who may not actively seek supervision during CrossFit exercise. Strength of Recommendation: Level 2b evidence from 3 retrospective cohort studies indicates that the risk of injury from participation in CrossFit is comparable to or lower than some common forms of exercise or strength training.
Brett Krueger, Laura Becker, Greta Leemkuil and Christopher Durall
Ankle sprains account for roughly 10% of sport-related injuries in the active population. The majority of these injuries occur from excessive ankle inversion, leading to lateral ligamentous injury. In addition to pain and swelling, limitations in ankle range of motion (ROM) and self-reported function are common findings. These limitations are thought to be due in part to loss of mobility in the talocrural joint. Accordingly, some investigators have reported using high-velocity, low-amplitude thrust-manipulation techniques directed at the talocrural joint to address deficits in dorsiflexion (Df) ROM and function. This review was conducted to ascertain the impact of talocrural joint-thrust manipulation (TJM) on DF ROM, selfreported function, and pain in patients with a history of ankle sprain.
Focused Clinical Question:
In patients with a history of inversion ankle sprain, does TJM improve outcomes in DF ROM, self-reported function, and/or pain?
Paul F. Greene, Christopher J. Durall and Thomas W. Kernozek
A torso-elevated side support (TESS) has previously been described for measuring endurance of the lateral trunk muscles. In some individuals, however, TESS performance may be hindered by upper extremity pain or fatigue. For this reason a novel test, the feet-elevated side-support test (FESS), was examined.
To determine intersession reliability of a FESS and a TESS on the left and right sides using a single examiner, to evaluate the relationship between tests, and to compare reasons for test termination.
Nonexperimental prospective repeated measures.
A convenience sample of 60 healthy participants from a university community (17 men, 43 women; age 21.1 ± 2.2 y; height 169.9 ± 9.5 cm; weight 67.1 ± 11.9 kg).
Intraclass correlation coefficient between 3 testing sessions = .87 with right FESS, .86 with left FESS, .78 with right TESS, and .91 with left TESS. Pearson correlation coefficients ranged from .59 (between left FESS and left TESS in women) to .75 (between left FESS and left TESS in men). Upper extremity pain or fatigue was the reason given for test termination in 42.5% of participants during the TESS and 5.0% during the FESS (P = .000, Fisher exact test).
FESS and TESS had comparable intersession reliability by the same evaluator. Moderate to high correlations were found between FESS and TESS scores, suggesting that the tests assess similar qualities. Far fewer participants terminated the FESS because of upper extremity pain or fatigue. Thus, the FESS may be a suitable alternative to the previously validated TESS, particularly for individuals with upper extremity pain or weakness.
Christopher J. Durall, Thomas W. Kernozek, Melissa Kersten, Maria Nitz, Jonathan Setz and Sara Beck
Impaired postural control in single-limb stance and aberrant drop-landing mechanics have been implicated separately as risk factors for noncontact anterior cruciate ligament (ACL) injury, but associations between these variables has not been reported.
To determine whether there are associations between single-limb postural control and drop-landing mechanics.
University motion-analysis laboratory.
Single-leg-landing kinematic and kinetic data were collected after participants dropped from a hang bar. Postural-control variables COP excursion and velocity were assessed during single-leg barefoot standing on a force platform.
A convenience sample of 24 healthy women.
Main Outcome Measures:
Pearson product–moment correlation coefficients.
Strong associations were measured between maximal knee-abduction moment and COP excursion (r = .529, P = .003) and average COP velocity (r = .529, P = .003). Strong inverse associations were measured between minimum hip-flexion angle and COP excursion (r = −.521, P = .003) and average COP velocity (r = −.519, P = .003).
Participants with decreased postural control had higher knee-abduction moments and a more extended hip on landing, which have been implicated separately as risk factors for ACL injury. A longitudinal prospective analysis is needed to determine whether force-platform postural-control measures can identify athletes at risk for ACL injury.
Ryan D. Henke, Savana M. Kettner, Stephanie M. Jensen, Augustus C.K. Greife and Christopher J. Durall
ClinicalScenario: Low-intensity aerobic exercise (LIAEX) below the threshold of symptom exacerbation has been shown to be superior to rest for resolving prolonged (>4 wk) symptoms following sport-related concussion (SRC), but the effects of LIAEX earlier than 4 weeks after SRC need to be elucidated. Focused Clinical Question: Does LIAEX within the first 4 weeks following SRC hasten symptom resolution? Summary of Key Findings: Two randomized controlled trials (RCT) and 1 nonrandomized trial involving adolescent athletes (10–19 y) were included. One RCT reported faster recovery time with LIAEX versus placebo stretching. Likewise, recovery time was faster with LIAEX versus rest in the nonrandomized trial, but not in the underpowered RCT, although effect sizes were similar between these studies (0.5 and 0.4, respectively). All 3 studies reported a reduction in concussion symptom severity with LIAEX; however, the magnitude of symptom reduction across the recovery timeline was greater in the LIAEX group than the rest group in the nonrandomized trial, but not the 2 RCTs. Importantly, no adverse effects or incidence of delayed recovery from LIAEX were reported in any of the studies. Clinical Bottom Line: LIAEX initiated within 10 days after SRC may facilitate a faster recovery time versus placebo stretching or rest, although additional clinical trials are strongly advised to verify this. Strength of Recommendation: Level 1b and 2b evidence suggests subsymptom exacerbation LIAEX may decrease Postconcussion Symptom Scale scores and hasten symptom resolution in adolescent athletes following SRC.
Lauren Anne Lipker, Caitlyn Rae Persinger, Bradley Steven Michalko and Christopher J. Durall
Clinical Scenario: Quadriceps atrophy and weakness are common after anterior cruciate ligament reconstruction (ACLR). Blood flow restriction (BFR) therapy, alone or in combination with exercise, has shown some promise in promoting muscular hypertrophy. This review was conducted to ascertain the extent to which current evidence supports the use of BFR for reducing quadriceps atrophy following ACLR in comparison with standard care. Clinical Question: Is BFR more effective than standard care for reducing quadriceps atrophy after ACLR? Summary of Key Findings: The literature was searched for studies that directly compared BFR treatment to standard care in patients with ACLR. Three level I randomized control trial studies retrieved from the literature search met the inclusion criteria. Clinical Bottom Line: Reviewed data suggest that a short duration (13 d) of moderate-pressure BFR combined with low-resistance muscular training does not appear to measurably affect quadriceps cross-sectional area. However, a relatively long duration (15 wk) of moderate-pressure BFR combined with low-resistance muscular training may increase quadriceps cross-sectional area to a greater extent than low-resistance muscular training alone. The results of the third randomized control trial suggest that employing BFR while immobilized in the early postoperative period may reduce quadriceps atrophy following ACLR. Additional data are needed to establish if the benefits of BFR on quadriceps atrophy after ACLR outweigh the inherent risks and costs. Strength of Recommendation: All evidence for this review was level 1 (randomized control trial) based on the Centre for Evidence-Based Medicine criteria. However, the findings were inconsistent across the 3 studies regarding the effects of BFR on quadriceps atrophy resulting in a grade “B” strength of recommendation.